Various engines/pumps utilizing a crank shaft are currently known. Such engine/pumps are more commonly known as wobble engines/pumps or swash plate engines/pumps. Wobble engines/pumps have axial pistons disposed from a wobble plate which is fixed on an output/input shaft at an acute angle. In the case of an engine, power received from the pistons is transferred to the wobble plate during the power stroke, displacing the wobble plate axially, and as a result rotating the shaft The operation of a wobble pump is in reverse order, wherein power is applied to the input shaft to displace fluid inside the cylinders.
Modern developments in wobble engines/pumps have included changes in the configuration and operation of the pistons/cylinders and in inlet/outlet porting of the fluids. The drive mechanisms of such modern machines are nevertheless very complex, requiring many parts which are both difficult to assemble and also difficult to maintain. Such engines/pumps also have a lot of components operating under high frictional forces.
Previously published New Zealand Patent No.221366 discloses therein a means to transfer the wobbling motion of a disc to a rotary motion of the shaft and visa versa. Further disclosed therein is a suitable means of providing power to or from the disc by way of internal cylinder engine or hydraulic/pneumatic motors. There is however no detail on any means by which the cylinder engine is or can be coupled to either the disc or the shaft, such that the invention can operate as a compact simple unit.
New Zealand Patent No.150235 describes a continuous disc acting as pistons inside a chamber. The disc is non planar and rotation thereof inside the chamber forms pockets which are compressed and expanded at differing angles of rotation.
The complex nature of the disc, output and crank shafts, chamber and other dependent mechanisms make such an engine/pump expensive and difficult to make.
New Zealand Patent No.131852 describes a two stroke or four stroke engine also operable as a pump, in which pistons of circular cross-section which are bent in an arc are located inside curved cylinders disposed axially about a central axis. Power from the rotating cylinders is transferred to the output engine block, the spider in this invention remaining stationary.
Most modern wobble type engines/pumps require many complicated parts to ensure efficient operation. Difficulties exist in the sealing of cylinders to ensure that no fluid escapes undesirably, and in the assembly and maintenance. Such engines also have problems operating in balance.
It is an object of the present invention to provide an engine/pump which will at least provide the public with a useful choice.